228 Proceedings of the Royal Physical Society. 
arms occurred, along with a tendency to reduction of tentaculocysts in the 
perradial arms. There was, however, one ten-rayed form due to doubling 
of two perradial arms, with “twin” tentaculocysts in another perradial arm. 
The ephyrez from strobila No. 8 showed variation in the interradial arms 
only. All degrees of doubling were found, from “twin” tentaculocysts 
in one interradial arm up to more or less complete doubling of the four 
interradial arms. Figs. 1-12 give a semi-diagrammatic representation of 
the chief variations found in this strobila. In strobila No. 10, reduction 
of the perradial arms occurred. Strobila No. 12 is of interest on account 
of the occurrence of a ‘“‘twin” specimen. The attachment between two 
succeeding ephyre had remained after their liberation from the strobila. 
The uppermost one was a twelve-rayed form, while the lower one was 
a normal eight-rayed type, showing that a large amount of variation occurs 
even between two succeeding ephyre from the same strobila. From 
strobila No. 27 only ephyre with four rays were liberated. The arms 
present were the interradials. 
An analysis of the twenty-seven strobile examined shows that— 
(a) Twenty-two per cent. of the strobilz produced only normal ephyre. 
(6) Forty-four per cent. of the strobile produced ephyre among which 
the variants varied in the perradial arms only. 
(c) Thirty per cent. of the strobile produced ephyre among which the 
variants varied, some in the perradial and some in the interradial 
arms. 
(¢q) Four per cent. of the strobile produced ephyre showing minor 
variation, ¢.g. in gastric filaments, only. (Arms normal.) 
SUMMARY OF EPHYRA? PRODUCED FROM THE VARIOUS STROBIL. 
Neer a Number 
Date reine ke of Notes 
phyre 
STROBILA | 14.2.20 8 6 
No. 1 ee 14 1 Possibly due to doubling of 3 perradial arms and 
doubling of 2 interradial arms, or to doubling of 
| 2 perradials and trebling of 2 perradials, with all 
| the interradial arms single. 
STROBILA | 24.2.20 Sif | 2 One perradial arm missing. 
No. 2 3; 7 1 One perradial arm missing, another without a tenta-. 
| culocyst. 
i. Gy iene 
¥ da | il Three perradial arms doubled. 
STROBILA | 14.2.20 8 | 8 
No. 3 - 11 | 1 Three perradial arms doubled. 
| 
